Gross Anatomy - Exam 4 Flashcards
What are the subdivisions of the GI system
Foregut, midgut, hindgut
Plane at T9 vertebral level
Xiphisternal plane
Plane at L1 vertebral level
Transpyloric plane
Plane at L3 vertebral level
Subcostal plane
Plane at L4 vertebral level
Supracristal plane
Plane at L5 vertebral level
Transtubercular plane
Plane at S2 vertebral level
Interspinous plane
Where is the suprapubic plane located?
No vertebral level. Located below S3
Where does the terminal portion of the esophagus enter the abdomen and stomach?
Abdomen at T10. Stomach at T11.
Where is the stomach located?
Tip of 8th costal cartilage at T11
Where is the pylorus located?
½ inch from midline at transpyloric plane (L1)
What are the parts of the stomach?
(4) Cardia, fundus, body, pyloric part
What is the name of the fold located in the stomach?
Gastric rugae
What are the curvatures of the stomach?
Greater curvature and lesser curvature
Intraperitoneal vs. retroperitoneal
Intraperitoneal – structures within the peritoneum, mobile
Retroperitoneal – structures outside the peritoneum, fixed location
What are the four parts of the duodenum and location?
1st part – anterior to posterior at L1
2nd part – fixed against body wall at L2
3rd part – fixed against body wall at L3
4th part – fixed against body wall at L2
Which part(s) of the duodenum are intraperitoneal? Which are retroperitoneal?
1st part – intra
2nd, 3rd, and 4th – retro
What are the folds within the small and large intestine called?
Plica circulares
What are the projections located within the duodenum and where do they drain?
Minor duodenal papilla – insignificant amount of pancreas
Major duodenal papilla – liver, gallbladder, and pancreas
Cystic Duct + Common Hepatic Duct = Common Bile Duct
Common Bile Duct + Main Pancreatic Duct = Major Duodenal papilla
How can you tell the difference between jejunum and ileum?
Jejunum – prominent plica circulares
Ileum – few/flattened plica circulares
Are the jejunum and ileum intra or retroperitoneal?
Intraperitoneal
Location of jejunum and ileum
Jejunum starts left of L2
Descends diagonal along root of mesentery to L5
Ends at ileocolic junction L5
How long is the jejunum? The ileum?
Jejunum – 7-8 feet
Ileum – 6-12 feet
Four characteristic features of large intestine
Taeniae coli
Haustra (segmental appearance)
Epiploic appendices
Plica semilunaris
What forms the appendix?
3 teniae coli coming together
Cecum and appendix location
Begins at transtubercular plane (L5)
Lies at interspinous plane (S2)
Ascending colon location
Extends from cecum to transpyloric plane (L1)
Transverse colon location
Begins right colic flexure (transpyloric plane L1)
Ends at left colic flexure T12
Descending colon location
Extends from T12 to transtubercular plane L5
Sigmoid colon location
Begins at transtubercular plane L5
Ends midline below interspinous plane S2
Order of pathway thru large intestine
Cecum/appendix > ascending colon > transverse colon > descending colon > sigmoid colon > rectum
What are the changes in direction in the large intestine?
Right colic/hepatic flexure
Left colic/splenic flexure
Determine whether each portion of the large intestine is intra or retroperitoneal
Cecum – intra
Ascending colon – retro
Transverse colon – intra
Descending – retro
Sigmoid colon – intra
Rectum – retro
What are the fat droplets on the intestine called?
Omental/epiploic appendices
Where is teniae coli NOT present in the large intestine?
Rectum
Location of upper and lower borders of the liver
Upper – T9
Lower – L3 on right, T9 on left
Four anatomical lobes of liver
Right, left, quadrate, caudate
What structures are found in the liver?
- Ligamentum venosum
- Ligamentum teres hepatis (aka round ligament)
- Porta hepatis (hepatic portal vein, proper hepatic artery, common hepatic duct)
Functions of liver
Synthesize plasma proteins
Production of bile
Detoxification
Glycogen storage
Production of hormones
What separates right and left lobes of liver?
IVC
What separates left and caudate lobes of liver?
Ligamentum venosum
What separates left and quadrate lobes of liver?
Ligamentum teres hepatitis/round ligament
What is in the portal triad? Where does it enter?
Portal triad: hepatic portal vein, proper hepatic artery, common hepatic duct
Enters liver at porta hepatis
Ligamentum venosum developmental origin
Ductus venosus
Ligamentum teres hepatis developmental origin
Umbilical vein
Name and location of the 4 parts of the pancreas
Head of pancreas – L2 (in ‘C’ of duodenum)
Neck, body, and tail – L2, L1, T12 (ends in spleen hilium)
Determine whether each part of pancreas is intra or retroperitoneal
Head, neck, and body – retro
Tail – intra
Which parts of the pancreas are considered “ventral pancreas”? Which parts are “dorsal pancreas”?
Head and neck – ventral
Body and tail – dorsal
What structures enter the pancreas connecting with major or minor duodenal papilla?
Main pancreatic duct (MOSTLY) to major duodenal papilla
Minor pancreatic duct to minor duodenal papilla
Gallbladder location
Tip of 9th costal cartilage on right at transpyloric plane (L1)
What drains the gallbladder?
Cystic duct into common bile duct
What are the arterial vasculatures and location?
- Celiac axis – T12
- Superior mesenteric – L1
- Renal (paired) – L2
- Gonadal (paired) – L2/L3
- Inferior mesenteric – L3
Branches of celiac artery
(3) Left gastric, common hepatic, splenic
Branches off common hepatic artery
(2) Proper hepatic and gastroduodenal arteries
Branches off proper hepatic arteries
(3) Right gastric, left hepatic, and right hepatic
Branch off right hepatic artery
Cystic artery
Branches off gastroduodenal artery
(4) Supraduodenal, right gastroepiploic, and anterior and posterior superior pancreaticoduodenal
Branches off splenic artery
(3) Pancreatic, short gastric, left gastroepiploic
Structure that surrounds greater curvature of the stomach
Greater omentum
What arterials anastomose at the greater curvature? What about the lesser curvature?
Greater: right and left gastroepiploic arteries
Lesser: right and left gastric arteries
What are the branches off the superior mesenteric artery?
- Anterior and posterior inferior pancreaticoduodenal
- Jejunal mesenteric
- Ileal mesenteric
- Ileocolic
- Right colic
- Middle colic
How to tell between the jejunum and ileum based on vasa recta and arcades
Jejunum: vasa recta are long and spread; arcades are large and fewer in number
Ileum: vasa recta are short and compact; arcades are small and layered
What are arcades?
Anastomotic loops located in small intestine
What are the branches off inferior mesenteric artery
(3) Left colic, sigmoid, and superior rectal arteries
Tributaries of portal vein
(2) Superior mesenteric and splenic veins
What are the portacaval anastomoses?
Esophageal veins, rectal veins, para-umbilical veins, and retroperitoneal veins (colic and splenic veins with body wall veins)
What are issues with using the anastomoses paths? Which vein is most life threatening if it breaks?
Blood is not clean and overworks these veins
Varacies: stretching or enlargement of vein
Esophageal vein is most life threatening
What germ layers are responsible for GI system
Mesoderm and endoderm
The GI is a hollow tube extending from ___ to the ___.
Buccopharyngeal membrane (future mouth); cloacal membrane (future anus)
Name of membranes resulting in future mouth and anus
Mouth: buccopharyngeal membrane (breaks down at 3rd week of development)
Anus: cloacal membrane (breaks down at 7th week of development)
Germ layer of epithelial lining of organs? Muscular walls and serous coats?
Endoderm – epithelial lining
Mesoderm – muscular walls and serous coats
What is the name of the cavity where the GI develops? What does it turn into?
Cavity: intraembryonic coelom
Future: peritoneal cavity
What are the subdivisions of the developmental digestive system?
Foregut, midgut, and hindgut
What is the arterial supply of the foregut?
ALL celiac artery
Esophagus (overlaps): celiac and esophageal arteries
Pancreas (overlaps): celiac and superior mesenteric arteries
(Duodenum parts 1 and 2)
Spleen is not a GI organ but also celiac artery
What is the parasympathetic innervation of the foregut?
Vagus/Cranial n. X
What is the arterial supply of the midgut?
ALL superior mesenteric
(Duodenum parts 3 and 4)
What is the parasympathetic innervation of the midgut?
Vagus/Cranial n. X
What is the arterial supply of the hindgut?
ALL inferior mesenteric
What is the parasympathetic innervation of the hindgut?
S2, S3, S4 aka. Pelvic splanchnics
What structures are part of the foregut?
(7) Esophagus, stomach, duodenum parts 1 and 2, liver, gallbladder, and pancreas
What structures are part of the midgut?
(8) Duodenum parts 3 and 4, jejunum, ileum, appendix, cecum, ascending colon, and transverse colon